Color photography.



" UNITE TATE \EAMBURGEB, or teams; nimm N .0 3 rnoroenunr.

1,059,867. No Drawing.

To all 'wkmrtit mayconcern: v

Be it known that I, A'CRQN HAMBURGER,

a citizen of the United States of America,

and residing at 38 Dover street, London, -W., England, have invented certainnew and useful Improvements in and Relatingto Color Photography, of which the following is a specification. v

.Dhis invention relates to the obtaining of color prints of photographs.

.Thrs inventionhas'safor its object to provide improved processes for the-production of ayellow tone in prints of photographs and to provide a'method of producingfcol'or photographs which su stantia'lly si-m-.

plifythe, methods heretofore -proposed=- 2 or other suitabldilight sensitive zimedium The invention c'onsistsm. aiprocess for. obtaining a yellow tone in prints of-I-photo-I graphs consisting bleaching an image obtained ona silver ch1orobro1nid, }or=g other suitable light sensitive mediumflto any' dc-'2 'extentredev the. "bleached .im

sired-extent and to I age "od1d print is' obtained on a" silvefhhlorbbroinid Efi-Qmthe negative-*corresponding'to thqyel-ilow-@101, then bleached to any". desired;

' "extent. and then {toned by'the action-"oit pd- 'tassium mercuric iodid oralkalimercuric:

iodide. 9; by the-action'ofe solution ob{' 'tained mixingsolutions of mercuric ch10 rid and -potassium iodid, whereby a ellow.

eolo'r print can be. obtained having a ey or foundaticmv off practioally panchromatic printofa, colorphoto a h having a key- 45101-" fonmla'tion of precise 1y panchromatic.

ne r-1; 7 ThiSjfiVQIltlOIl further consists ma ye lv 10W color print theyelloW'tone-of vwhich-1s due to a mercury-silver iodid' f j This nventlon further cons sts m a color T he invention-is based on the "discovery that if a silver'printbebleached by .aJsuitable. bleaching solution such as :p'otassimh bromid and potassiumierricyanid and then developed ortonedwith a "solution obtained A by mixing mercuric 'chloridand otasslum iodidsolutions in suitable .pro or-trons e1- slow print of good quality is o e r- ".ther if the print so-treatedbe ode- Obtained from the negative corresponding" yel-" low of a three color photograph the resu t sp}:tinisati n or netieisrateut. P

?.A NT

is: gant photograph is of .particlilar brilliance and accuracy in; color reproduction. This obtained ffrom the, negative corresponding of fbleaching-ikvaryin particular subject.

1 three negatives commonly made of, the

desired'three colors. Thefilteruse 'T'for'ithe tbfthe yellow color of e. object isrpompose not only-or an image 1corresfionclin'g 'to the .yel'low components; but -al so -c'ontains an image of less intensity 1 formedjirom rays vpplrllents of .the'. f'objec't photographed.

en such a,

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com

r 'tenteunprzezneis. 'Applicatin flled Hay27,191"2. Serial 30.760351. P

isapparently due'to the fact that the print 4 to the yellow coloris'more or less panchrof iob'jecflto be photographed; each through a separatebolorfilter, c orrespondi' (to the .ylloviv .isimperfect in its action"inlfilt'erin'g t e jh -j 7 a oma y-imp n 'obtainedgirom thene ative corresponding is "the pamhiicimatic.

med with-fire corresponding red and.

above described '0 aces theyellow tone lanat1o of j; matmP- :iimithespecification to modify: Y

fango:-.three color' photographs :a... set of corresponding. .--to the. other color cdm-- --blue prints, made in any suitable manner,

-tain compensation for the necessary inac-' the resultant color photograph is formed with an underlying faint gray-key or image. This key results, when the three color prints are assembled, as stated,'in effecting a cercuracies of the process of negative-making,

' with the result that in the resultant color J 10% aluminium nitrate. "1 part 0 nitric photograph remarkably fine efiectsand accurate reproduction of colors are produced.

In carrying out the process in obtaining.

color prints for color photographs in one form a bromld or chlorobromid print is first obtained from the negative correspond" acid. 15 parts ofacetic acid. '50 parts -of water.

. v -The bleaching is carried. out'untilafaint gray image only remainswhen after washing -as usual the print is immersed in the following tonin solution 2-40 parts of 6% mercuric chlori solution. parts of8% potassium iodid solution. -lVhen the desired tone is attained the prints are removed and washed in the usual way. g It is to be observed that the tone continues to develop after completion of the immersion in the toning bath and allowance must be made for this in determining the time of withdrawal. The yellow can be arrested by immersing "the print in an acid bath at any time during the toning. In this way aprint is obtaine in a fine yellow color which corresponds to: .the yellow portion of the picture being produced and which possesses a key; or founda tion of practically panchromatic gray. This has been obtained in one operation without special skill and avoids the need a fgregistration or fixing necessary where a sepkately produced panchromatic 'key or I fouildation is employed as has'been proposed. The print so obtained can now in 'anyfsuitable. way be combined with the remaining color prints which may be of any suitable kind.

It will be understood that the present invention "may be applied to prints on transparent or translucent media as well as to prints on an opaque base."

The print which is treated may be one obtained on a bromid, chlorofbromid or other silver or suitable salt containing light sensitive medium and the bleaching solution formation of.

may be of any suitable kind, 0. 9. it may be 'a chromic acid or bichromate bleaching solution.

It is who understood that the methods of obtaining the mercury silver iodid image and of obtaining the print with "a gray key or foundation above described are referred to byway of example only and may be considerably varied without departing from the spirit of the present invention.

' Having now described my invention what I claim as new and desire to secure by Let-' ters Patent is z- IQA process for obtaining a colored photo-- graphic print suitable for combination with prints of other colors to form a resultant color photograph, consisting in making a negative of the object to be reproduced through a. yellow filter,- making a print therefrom on a silver-containing light-sensi- .t-ive medium, bleaching the print until only a faint gray image remains, washing, toning in a suitable mecurlc iodid solution, until a yellow tone is obtained, removing from the solution and washing, substantially as described. r

. 2. A process for obtainin a colored photographic print suitable. or combination with sultant color photographconsisting in making a negative of the o ject to be reproduced through a yellow filter, making a print therefrom on a silver-containing light-sensitive-medium', bleaching the image to. any'desired extent, and toning the bleached image ina solution obtained 1) y mixing solutions of mercuricchlorid and potassium iodid until a yellowtone is obtained, and removing from the solution and washing, substantially as described.

3. A process for obtainin a' colored photographic print suitable printsmf other colors to form-a. 'reor combination with prints of other colors to form a resultant color photograph, consisting in making a negative of the object to be reproduced through a yellow filter, making a print therefrom on a silver-containing light-sensitive medium, bleaching the' image to any desired extent in a solution of potassium bromid and potassium ferri-cy anid and toning the bleached image in a suitable mercuric iodid solution until a. yellow tone is obtained and removing from the solution and washing, substantially as described.

4. A process for obtaining a colored photographic print suitable for combination with prints of other colors to form a resultant color photograph, consisting in making a print on a silver-containing light-sensitive medium, bleaching the same until only a faint gray image remains. and toning the bleached image in a suitable mercuric iodid solution until a yellow tone is obtained and removingfrom the solution and washing, substantially as described.

' therefrom on a of substantially 8 per cent. potassium .lng a negative of A process for obtaining a colored photographic print suitable for combination with prints of other colors to form a resultant color photograph, consisting in mak the object to be reproduced through a yellow filter, making a print silver-containing-light sensitive-medium, bleaching the image to any desired extent and toning the bleached image in a suitable mercuric iodid solution until the desired yellow tone is obtained, removing the print from the'solution, immersing in an acid bath to arrest further formation of the yellowcolor and washing, substans tially as described.

6. A process for obtaining a colored photographic print suitable for combination with prints of other colors to form a re sultant color photograph, consisting in mak-' ing a print on a silver-cont-aining-light-sensitive medium from a negative of the yellow portion of the object to be reproduced, bleaching the print until only a faint gray image remains, washing andtOning'in a solution formed by mixing to ether approximately 40 parts of substantially 6 percent. mercuric chlorid solution and 60 parts iodid solution, and removing from the solution sa new article of manufacture, a yellow color print having a key or foundation of gray, the yellow tone of which print is due to a mercury silver-iodid, substantially as described. f v

8. As a new article of manufacture, a phovtographic color print having yellow elements representing selectively the; yellow components only of the object photographed, which yellow elements are caused byiodids of mercury and silver, substantially asde. scribed. 9. As a new article of manufacture, a photographic color print of a permanently bright yellow corresponding selectively to the yellow components only of the object photographed and due to a mercury silver iodid, the said print having a key or foundation of practically panchromatic gray, substantially as described.

This specification signed and witnessed this 17th day of May 1912. Y

Witnesses: v D. J. JOHNSTON, G. E. HOSKINS.

ARON HAMBURGER. i 

